Ok a few answers since I play a bushido/paladin archer.
Bushido is good for archers for a couple reasons. 1) The main reason is honoring monsters so you do extra damage. This in itself is the MAIN reason for having bushido on a archer. In fact its much more important than having tactics except in rare situations. Solo hunting, Honor/bushido is infinitely better than having high tactics.
2nd, you can use lightning strike to increase damage occasionally. This works very well if you have decent mana regen due to weapon/armor. HCI plus the rare chance of more damage. That rare crit hit really increases damage on some foes.
Other than that, bushido isn't used for much else, even though a few powers can benefit you, but the main 2 are honoring and lightning strike. Bushido on archers is all offensive, no defense. You will greatly notice alot more damage vs foes when using honor/lightning strike in conjunction with your paladin abilities. But note, this build is greatly MANA intensive, especially since they nerfed both bow mana leech, plus mana regen suits for warriors.
120 archery (a must)
100 tactcs
100 healing
100 anatomy
100 resist
100 bushido
80 chivalry
This is a great basic layout for a archer/paladin samurai. You can get some catagories higher with items/age/adjustment. After this, work on raising bushido and chivalry up. tactics and anatomy don't need any more unless you are going for a specialized doom/peerless group archer. Tactics and anatomy over 100 provide a minimal damage boost compared to 120/120. Much better to have your bushido and chivalry up. You might even want tactics at 90 until you get higher in max skill levels.
The perfect layout would be close to
120 archery
120 bushido
100 tactics
100 healing
100 anatomy
100 resist
100 chivalry
so get as close to that as possible.
Now, as to focus. Focus would help you alot in this template, but sadly its a very tight template and focus isnt usually used. But you have to make sure you have a bow with high mana leech, plus a mana regen suit. Even with this you will be short on mana alot. If you switch focus for resist, your regens are a little better but you are easily smacked around with curses/poisons/paralyzes. A huge difference if you don't have any resists. I suggest keeping the resists.